Tightening device for boiler-tubes.



No. 785,888. PATBNTED MAR. 28, 1905. P. J. BJOHANSSON.

TIGHTENING DEVICE FOR BOILER TUBES.

APPLIOATION FILED FEB. 8. 1904.

2 SHEETS-SHEET l.

222 I I 1W Z/AZ No. 785,888. PATENTBD MAR. 28, 1905 F. J. E. JOHANSSON.

TIGHTENING DEVICE FOR BOILER TUBES.

APPLICATION FILED man. a, 1904.

2 SHEETS-SHEET 2.

Wijizess as. 77/U67Z Z07.

Patented March 28, 1905.

PATENT OEEIcE.

FRANS JOHAN EMIL JOHANSSON, ()F STOCKHOLM, SWEDEN.

TIGHTENING DEVICE FOR BOILER-TUBES.

SPECIFICATION forming part of Letters Patent No. 785,888, dated March 28, 1905.

Application filed February 8, 1904. Serial No 192,689.

To all whom, it nuty concern.-

Be it known that I, FRANS JoHAN EMIL J OHANSSON, a subject of the King of Sweden and Norway, residing at Stockholm, Sweden, have invented certain new and useful Improvements in Automatic Tightening De vices for Boiler-Tubes; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters of reference marked thereon, which form a part of this specification.

This invention has relation to tubular boilers either of that type known as water-tube boilers or the type known as combined water and fire tube boilers.

One of the essential objects of my invention lies in a self-tightening connection between the water-tubes or the combined water and fire tubes and the headers for said watertubes.

A further important object of my invention lies in the connection of the headers for each series or set of tubes with the upper and lower circulation pipes whereby any one of the sets of tubes may be readily removed, if this becomes necessary from any cause, and replaced even while the boiler is in operation.

A further object of my invention lies in the provision of means to protect the resilient or elastic headers from injury by heat.

Finally, the invention has for its object certain details of construction and combinations of parts whereby the results aimed at are attained but that my invention may be fully understood I will describe the same in detail, reference being had to the accompanying drawings, in which Figure 1 is a front elevation, partly in section on the broken line A B, of Fig. 2, which latter is a section on the broken line C D of Fig. 1. Fig. 3 is a longitudinal section of one of the water-tubes, showing its connections to the headers and also showing means to protect the latter from injury by heat. Fig.

4 is a longitudinal section of a combined water and fire tube, showing the connections of the former to its headers; and Fig. 5 is a longitudinal section of a water-tube, showing a modification of the connections thereof to its headers.

Referring to Figs. 1 and 2, wherein I have shown as an example a boiler having its tubes arranged in converging planes, S indicates the boiler shell or housing of substantially conical form in cross-section; t, the steamdrum; 8*, a downtake at the rear end thereof connected through pipe .3 with the lower circulation-pipe s, to which the boiler-feed pipe .9 is connected. 1* is a V-shaped union pipe or uptake connecting the upper tube-headers at one end to the forward end of the steamdrum below the level of the water therein, as shown at r and 1- Fig. 1. G indicates the grate, and t the steam-distributing pipe. In said Figs. 1 and 2 I have shown as an exam plc a boiler having four sets of water-tubes on either side, each set or group being com posed of eleven tubes, though it is understood that I do not limit myself thereto nor to the relative arrangement of the sets of tubes, which may be varied according to the form and uses made of the boiler. As shown in Fig. 2, all the water-tubes b of each set,

except the forward tube 6*, are closed at both ends, communication between them and their headers a a being established as hereinafter described, while said ends of the forward tube b of each set of tubes are also in direct communication with and removably secured to valve-boxes a and v, respectively, containing cut-off valves, the stems if of which may project through the front wall of the boiler above the doors D thereof or may be covered by said doors or project through suitable apertures therein, so that ready access is had to the cut-off valves, whereby any one of the sets of tubes can be cut out of the circulation and by unscrewing the nuts a re moved from the boiler should this become necessary from any cause and replaced without interfering with the function of the other sets of tubes. The valve-boxes u and l), as shown in Fig. 2, are interposed in the pipes leading to and from the upper and lower circulation-pipes r and s, respectively.

I will now describe the connections between the tubes of a set and their upper and lower headers c and a and the means for protecting the same against the action of the furnace heat, referr ng more particularly to Fig. 3. v

The tube 1) is open at both ends and near each end is provided with peripheral ports a and with an external flange (1, both ends of the tube being screw-threaded externally, and as the connection thereof to the headers c a is the same at both ends of the tube a description of one end connection will suffice.

The header a, of sheet metal, is of elliptical or other similar suitable form in cross-section and preferably of increased thickness between the rounded sides, as shown at a said sides being comparatively thin, thereby rendering the headers more or less elastic or yielding to pressure both from within and without. The lower edge of the opening in the header a seats on the aforementioned flange (2, while the upper edge abuts against a screw-cap c, screwed onto the end of tube 1) to close the same. The header a is thus held compressed between said flange and cap, and in view of the elasticity or resiliency of said header a tight oint is formed between it and the tube, and it will readily be seen that the greater the pressure within the tube the tighter will be the joint between it and the header. I am thus enabled not only to maintain a much higher boiler-pressure than would be the case in a similar boiler of usual construction, but I am also able to dispense with either permanent connections between header and tube or packed connections, while the removal and replacing of any of the tubes, when this becomes necessary, is greatly facilitated.

In view of the fact that the headers c are quite sensitive to pressure variations and to avoid excessive collapsing or contracting, I make use of a stay or brace, which, as

shown in Fig. 3, is a short cylinder or sleeve of greater diameter than the tube 1) and having peripheral ports h, registering with the tube-ports c, said sleeve being introduced into the header a and forming a bearing for its upper and lower walls when compressed by the screw-cap c, and to prevent displace ment of the sleevefit is provided at one end with an internal flange which fits the tube b snugly, as shown.

In order to protect the comparatively thin concave-convex sides of the header from injury by heat, I cover them, if necessary, with a shield 0, as shown in Fig. 3.

As shown in Fig. l, the connection between the water-tube b of a combined water and fire tube and its header a is substantially the same as that described in reference to Fig. 3, with the exception that the compression of the headers is effected by a nut 0, while the fire-tube b is centered in the water-tube I) by means of a nut c at one end, which. nut also closes the upper end of said water-tube I), while the lower end of the firetube is expanded and stepped, as shown at l) I), to form a bearing for the lower wall of the lower header a and for the bracingsleeve f, and in said Fig. 4 I have shown the watertube as being corrugated to increase its heating-surface and expansibility. It is obvious that by screwing on the nuts 0 the upper header a can be compressed to the desired extent and that by screwing the nut 0 onto the upper end of the fire-tube b the lower header a can be compressed to the desired extent and the upper end of the water-tube hermetically closed, the internal diameter of the nut 0 being less than that of the watertube 5. The same result may be obtained by the construction shown in Fig. 5, wherein the ends of the water-tube b are expanded and then contracted to form the seats for one edge of the apertures in the headers a and a, while a bar m, extending the full length of the tube, is provided with an upper externally-threaded circular head m for the re ception of the compressing and closing cap 0, while at its lower end said bar has an enlarged circular stepped head m, forming a bearing for the lower wall of the lower header a. As shown in Fig. 5, the water-tube 5 does not extend through the headers a and a, as the case in the construction shown in Figs. 3 and 4, but only through proximate walls of the headers a and a and only as much as is necessary to provide a seating for said headerwalls and a bearing for the bracing-sleeves to prevent their accidental dis placement. It is obvious that by screwing the cap 0 onto the upper head m of the bar m both upper and lower headers can be com pressed to the desired degree, so as to be firmly held between the sleeves f, the seat flanges (Z, and the heads m m of bar m.

In the construction last described the bar on also performs the function of a stay for the water-tube 6 which is also the case in the construction shown in Fig. 4, where the firetube 5 acts as a stay for the water-tube I). On the other hand, when a stay-bar m is employed water-tubes of correspondingly increased diameter must be used, and to obviate this the said bars may be interposed between: each two water-tubes, should the space between them permit this, an arrangement which will be obvious to any boilermaker and which I have deemed unnecessary to illustrate, and whereby the sets of tubes and their headers may be more securely united without interfering with the ready removal of the tubes or the bars, should this become necessary from any cause.

In so far as the detachable connection of the headers a c to the valveboxes u and v is concerned the nuts n, hereinbefore referred to, are coupling-nuts that couple the ends of the water-tubes to the short branches u and o of said valve-boxes u and 1), respectively, as will be readily understood.

Obviously my invention is applicable generally to groups of tubular conduits for fluids unier pressure having a header at one or both en s.

Having thus described my invention, what I claim as new therein, and desire to secure by Letters Patent, is

l. The combination with a group of tubular conduits for a fluid under pressure; of expansible and compressible headers, means to limit the compression thereof and means to connect the tubes thereto, for the purpose set forth.

2. The combination with a group of tubular conduits for a fluid under pressure; of expansible and compressible headers, means to limit the compression thereof, and means to compress the headers and to simultaneously secure the tubes thereto, for the purpose set forth.

3. The combination with a group of tubular conduits for a fluid under pressure, said conduits provided near each end with a peripheral seat and with peripheral ports intermediate said seats and ends of the conduits; of expansible and compressible headers having apertures for the ends of the conduits and seating on the seats thereon, and means to compress the headers and close the ends of the tubes, for the purpose set forth.

4. The combination with a group of tubular conduits for a fluid under pressure, said conduits externally threaded at each end and provided with a peripheral seat and with peripheral ports intermediate said seats and threaded ends of expansible and compressible headers having apertures for the ends of the conduits and seating on the seats thereon, and screw-caps screwing onto the tube ends to close the same and to compress the headers, for the purpose set forth.

5. The combination with a group of tubular conduits for a fluid under pressure, said conduits provided near each end with a peripheral seat and with peripheral ports intermediate said seat and ends of the conduits; of expansible and compressible headers having apertures for the ends of the conduits and seating on the seats thereon, means to compress the headers and to close the conduit ends and means to limit the degree of compressibility of the headers, for the purpose set forth.

6. The combination with a group of tubular conduits for a fluid under pressure, said conduits provided near each end with a pe,

ripheral seat and with peripheral ports intermediate said seats and ends of the conduits; of expansible and compressible headers having apertures for the ends of the conduits and seating on the seats thereon, means to compress the headers and to close the conduit ends and means within the headers to limit the degree of compression of the headers, for the purpose set forth.

7. The combination with a group of tubular conduits for a fluid under pressure, said conduits provided near each end with a pcripheral seat and with peripheral ports intermediate said seats and ends of the conduits; of expansible and compressible headershav ing apertures for the ends of the conduits and seating on the seats thereon, means to compress the headers and to close the conduit ends, and bracing-sleeves within the headers encompassing the tubes and having ports registering with those in the tubes, substan tially as and for the purpose set forth.

8. The combination with a group of tubular conduits for a fluid under pressure; of expansible and compressible headers of substantially elliptical form in cross-section, means to connect the conduits to and to compress the headers and means to limit the compression thereof, for the purpose set forth.

9. The combination with a group of con centric boiler water and fire tubes, said water-tubes provided with externally-threaded ends, with peripheral seats near said ends and with peripheral ports intermediate said seats and ends; of expansible and compressible headers provided with apertures for the tube ends and seating on the seats thereon, means to compress the headers and means to center the fire-tubes within the water-tubes and close the ends of the latter, for the purpose set forth.

10. The combination with the steamdrum, the downtake, the uptake and the circulation-pipe; of separate groups of boilertubes and their headers, separate connections connecting opposite ends of the end tube of each group with the uptake and the circulation-pipe respectively, and cut off valves interposed between said connections and said uptake and circulation-pipe respectively, whereby any one of the groups of tubes may be removed and replaced without interfering with the other groups, substantially as set forth.

1 1. The combination with agroup of boilertubes, of headers made of resilient sheet metal, means to connect the tubes to the headers and an external protective covering for said headers, for the purpose set forth.

12. The combination with a group of boilertubes; of resilient headers whose top and bottom walls are thicker than the side walls, means to connect the tubes to said thicker walls and to compress the headers, and protective shields applied externally to the thin- 1r ler 1Eside walls thereof, for the purpose set ort 1 3. The combination with a group of boilertom walls are thicker than the side walls In testimony that I claim the foregoing as thereof, means to connect the tubes to SL1Cl I my invention Ihave signed my name in pres- 1o thicker walls and to compress the headers ence of two subscribing witnesses. into a substantially elliptical form in cross- 1 j Y Y 5 section, and sheet-metal protective shields JOHN JOHMSSOB secured externally to said side walls so as to Witnesses: leave a space between the two, for the purpose KoNR. DAI-ILQVIST, set forth. L. KALLENBERG. 

